* Astronomy

Blobrana · L

RE: Higgs Particles

Blobrana · L

UK Higgs Update: It's a boson!

The next step will be to determine the precise nature of the particle and its significance for our understanding of the universe. Are its properties just as expected for the Higgs boson predicted in 1964, the final missing ingredient in the Standard Model of particle physics? Or is it something more exotic? The Standard Model describes the fundamental particles from which we, and every visible thing in the universe, are made, and the forces acting between them. All the matter that we can see, however, appears to be no more than about 4% of the total. A more exotic version of the Higgs particle could be a bridge to understanding the 96% of the universe that remains obscure.
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Higgs boson-like particle discovery claimed at LHC

The CMS team claimed they had seen a "bump" in their data corresponding to a particle weighing in at 125.3 gigaelectronvolts (GeV) - about 133 times heavier than the proton at the heart of every atom.
They claimed that by combining two data sets, they had attained a confidence level just at the "five-sigma" point - about a one-in-3.5 million chance that the signal they see would appear if there were no Higgs particle.
However, a full combination of the CMS data brings that number just back to 4.9 sigma - a one-in-two million chance.
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Latest Results from ATLAS Higgs Search

On 4 July, 2012, the ATLAS experiment presented a preview of its updated results on the search for the Higgs Boson. The results were shown at a seminar held jointly at CERN and via video link at ICHEP, the International Conference for High Energy Physics in Melbourne, Australia, where detailed analyses will be presented later this week. At CERN, preliminary results were presented to scientists on site and via webcast to their colleagues located in hundreds of institutions around the world.
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Observation of a New Particle with a Mass of 125 GeV

CMS observes an excess of events at a mass of approximately 125 GeV with a statistical significance of five standard deviations (5 sigma) above background expectations. The probability of the background alone fluctuating up by this amount or more is about one in three million. The evidence is strongest in the two final states with the best mass resolution: first the two-photon final state and second the final state with two pairs of charged leptons (electrons or muons). We interpret this to be due to the production of a previously unobserved particle with a mass of around 125 GeV.
The mass of the new particle is determined to be 125.3 ± 0.6 GeV, independent of any assumptions about the expected relative yields of the decay channels. The measured production rate (sigmaDAT) of this new particle is consistent with the predicted rate (sigmaSM) for the SM Higgs boson: sigmaDAT/sigmaSM = 0.80 ± 0.22.
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Something like the Higgs boson has been found

Joe Incandela, the CMS Spokesperson, on CMS progress on the search for the Higgs Boson, 4 July 2012:

We've observed a new particle. We have quite strong evidence that there's something there. Its properties are still going to take us a little bit of time. But we can see that it decays to two photons, for example, which tells us it's a boson, it's a particle with integer spin. And we know its mass is roughly 100 times the mass of the proton. And this is very significant. This is the most massive such particle that exists, if we confirm all of this, which I think we will. And this is very, very significant. It's something that may, in the end, be one of the biggest observations of any new phenomena in our field in the last 30 or 40 years, going way back to the discovery of quarks, for example. We see very, very strong evidence of the decay to two photons, and a very narrow peak in the distribution. We see also the evidence of the decay to two Z-particles, which are like heavy photons, in this particular theory of elementary physics.

Blobrana · L

Higgs boson video leaks to Cern website

The Cern physics laboratory near Geneva appeared to leak crucial details of its hunt for the long-sought Higgs boson particle on Tuesday when it accidentally posted a video announcing the discovery of a new particle on its website.
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Higgs excitement at fever pitch

Scientists at the Large Hadron Collider (LHC) are expected to reveal on Wednesday the strongest evidence yet for the Higgs particle.
Anticipation is high and rumours have been rife about the announcement.
The Higgs boson would help explain why particles have mass, and fills a glaring hole in the current best theory to describe how the Universe works.
The strength of the LHC's signal is understood to be just short of the benchmark for claiming a "discovery".
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Why the Higgs Particle Matters

Most of us learned in school, or from books, that all the materials around us - everything we eat, drink and breathe, all living creatures, and the very earth itself - are made from atoms. These come in about 100 types, called "the chemical elements", and are typically found arranged into molecules, as letters can be arranged into words. Such facts about the world we take almost for granted, but they were still hotly debated late into the 19th century. Only around 1900, when the actual size of atoms could finally be inferred from multiple lines of reasoning, and the electron, the subatomic particle that inhabits the outskirts of atoms, was discovered, did the atomic picture of the world come into focus.
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Physicists Inch Closer to Proof of Elusive Particle

On Monday, Fermilab, in Batavia, Ill., said its results were the best "indication" so far that the legendary particle exists.
In what amounts to a last hurrah for the Tevatron, Fermilab physicists said that when they combined the data from some 500 trillion collisions of protons and antiprotons recorded since 2001 there was a suspicious excess, a broad bump in the mass range between 115 billion electron volts and 135 billion electron volts, in the units physicists use to measure mass and energy.
The new analysis confirmed an earlier one reported last March.
The odds that the Fermilab bump were due to chance were only one in 550, they said.
Unfortunately, that is just shy of the one part in 3,000, or "3-sigma" in physics jargon, that is required to use the word "evidence," let alone "discover," leaving the Tevatron unable to settle the question of the elusive boson.
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